Myxoid liposarcoma is a mesenchymal malignancy that most commonly presents in young adults, with peak incidence between the ages of 30-50 years. The clinical behavior of myxoid liposarcoma has been well characterized in adults. However, little is known about the clinical features and treatment outcomes of myxoid liposarcoma in child, owing to its rarity. This case report describes an 11-year-old previously healthy female who presented with a painless mass in her right thigh. Ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a soft tissue mass with clear margins in the subfascial plane superficial to the gracilis and sartorius muscles. She was diagnosed with myxoid liposarcoma based on histological and molecular cytogenetic examinations of the core-needle biopsy specimen. The patient subsequently underwent wide resection without any adjuvant treatment. The patient has not experienced any symptoms of local recurrence and metastases as of 2.5 years after surgery.